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Mixin apply for mod failed
COAL-011 · Mixin failed to apply
A mod's Mixin could not patch the code it targets - nearly always a Minecraft or mod version mismatch. How to identify the mod and get the versions lined up.
What it looks like in the log[main/ERROR]: Mixin apply for mod somemod failed org.spongepowered.asm.mixin.injection.throwables.InjectionError: Critical injection failure
What it means
Mixin is how most modern mods modify Minecraft: at load time they patch specific methods in the game's own code. Those patches are written against one exact version. If the method moved, changed shape, or vanished - because you are running a different Minecraft version than the mod was built for - the patch cannot be applied, and the mod aborts the launch rather than run half-patched.
How to fix it
- The mod ID is in the message -
somemodin the example above. That is your culprit; there is no need to bisect the mod list. - Check its supported Minecraft version on Modrinth or CurseForge and install the build for your server's exact version. "Works on 1.21" is not the same as 1.21.1.
- Update its dependencies too. When a mod mixes into another mod's code rather than Minecraft's, an outdated copy of that other mod produces the same failure.
- If two optimisation mods are fighting over the same method, removing one usually resolves it - a common outcome between competing performance mods.